With current technology, imaging is now at a pretty impressive level, immersing the viewer in a mind boggling artificial reality.

What creates 3D?

Seeing with two eyes creates our depth impression of the world. The best way to understand this is to do a practical experiment. Hold a finger up about 50 cm's away and focus on this finger observing the background at the same time. Everything towards the fixation point, your finger, becomes converged in your eyes. Move another finger from near your eyes towards the 'fixed' finger. Notice how it goes form being two images to one as it gets closer to your 'fixed' finger. The brain has many clues from image convergence and divergence to interpret depth. In fact, much of what we see as a single image is actually an illusion. The two differing images are recognised by us as a single image and the differences calculated in our brains to be the depth.

To recreate this in a picture two separate images are needed, one for each eye. With the Liquid crystal (LC) shutter glasses method, the left eye image and right eye image are created on a monitor sequentially. The glasses act as shutters, so that the left eye is allowed a certain amount of time viewing the screen when the left eye image is present, and then the right is allowed a certain amount of time when the right eye image is present. This sequence is repeated as the images change over time. The glasses are synchronised with electronics connected to the graphics board output via a dongle. These tell the glasses to go clear when the correct image appears on the screen. When this is done at a high speed the switching is not detectable. For most viewers a monitor refresh rate of 85Hz and above is recommended. The higher the better.

How does this work on a computer?

Nvidia have created additional software drivers that compliment their standard graphics board drivers. (They must have the same version number or they will not work properly). These are totally free and can be downloaded from their web site.

What they do is detect 3D game information from the programming language sent to the graphics board. When it is written in Open GL or Direct X the software generates two images as if the viewer were in two slightly different locations i.e. two eyes. This interprets as a left and right eye image. The left eye and right eye pictures are created and presented on your monitor in a time sequential order and sync pulses are sent to the glasses' dongle to operate the glasses in time (Page Flip mode), or they can be interleaved with lower and upper scan lines sequentially presented, again synced with the dongle to the glasses.

Nvidia also offer an additional program with the stereo driver download (called nVidia Stereo Viewer) for viewing internet and other computer generated stereo images in the .JPS format. JPS images are basically two jpegs side by side. During game play it is also possible to save screen shots by typing Alt F1. These are saved in a folder C:\NVSTEREO.IMG, ready for viewing with the nVidia viewer or with an appropriate 3D viewer such as the stereo applet used on this site.

Non-Nvidia
At the moment only eDimensional have written cost effective drivers that will support non-Nvidia graphics boards to give stereo 3D output. Their method of operation is similar to Nvidia's drivers except they work in tandem with what ever graphics board driver you have installed. This is great news for ATi fans. It is not as comprehensive a driver as nVidia, so not as reliable at performing 3D integration with current games, but it does give non nVidia board owners a chance at viewing 3D material.

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Conclusion
The shutter glass method is by far the most stunning for it's cost. Images are in true colour and detail is in fact enhanced because of the dual imaging, the brain has two sets of information to work on giving a more detailed mind image. An analogy of this could be when you listen to music in mono and then switch to stereo, you will notice so many more nuances.

These glasses can be used for 3D internet viewing of images, movies and VRML interactive content. On PC's you can view images and play incredible 3D games.
With appropriate software they can also be used for watching 3D DVD movies, and with conversion software view standard 2D videos and PC TV in 3D, converted in reel time on your PC. Check out the Utilities page on this site for viewing and producing 3D imagery.

3D viewing applications are diverse and have many professional uses other than gaming, such as educational and creative processes including, 3D graphic design, CAD/CAM, architecture, medicine and so on. The Victorians may have started this as an interest but the real impact of their concepts is starting to be fully realised now. And within the next few decades, if not years we should hear.. "Computer, open holo-deck doors!" Wishful thinking? I don't think so.

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